We had a very mean rooster who decided that everyone but me had to die. He didn't fly at me - but he got a hankering for the liver of small kids...so he had to go!
He was delicious - but as a barnyard rooster we definitely cooked him up as cock au vin or he would have been inedible.
The flapping and carrying on after death is going to happen no matter which method you use - chickens evolved from therapods, and they're pretty dinosaurian even now. Their nervous systems are designed to keep them going despite appalling injuries, and they really don't fall over flat until there's just nothing left. The brain can have checked out five minutes before, but the body won't know it.
I'm a small person iRL and I use the broomstick method (you can google it) as it's fast, instant, and
not bloody. Every single time I've had to put a chicken down, I've used it, freaked out because the wings were flapping, tried it again, then the head's, uh, come off. Because every single time, I broke the neck in one go and the bird was instantly dead. It's pretty foolproof, and it's not upsetting for you or the chicken.
That is, it's not upsetting until you do it twice out of a need to be 'completely humane' and are then wearing a chicken head.
If it helps at all, birds are descended from Coelurosauria - so visualise yourself versus a velociraptor...
(Not that hard to do with an angry rooster!)